A rapid gas chromatographic determination of thiamphenicol in plasma and amniotic fluid.

A rapid gas chromatographic method for the determination of thiamphenicol in plasma and amniotic fluid is described. The antibiotic is extracted from biological fluids with ethyl acetate and, after concentration of the extract, the trimethylsilyl derivative of the drug is determined by electron-capture gas chromatography using a 63Ni detector. After the intravenous administration of a single dose of 500 mg of thiamphenicol during the first stage of spontaneous labour to clinically normal gravidae at term, transmission of the drug across the placenta was demonstrated by a combination of gas chromatography and mass spectrometry.